JERUSALEM—Russia has begun to deploy an air force contingent to Syria in order to undertake air attacks against the Islamic State (IS, also known as ISIS or ISIL) and other Islamic groups battling the regime of President Bashar al-Assad, according to the Israeli news site, Ynet.

Citing western diplomatic sources, Ynet reported Tuesday that an advance Russian party has already arrived in Syria and will be followed in the coming weeks by thousands of military personnel, including members of an "aerial protection division." This presumably is a force to protect the air contingent, which is to include fighter jets and attack helicopters, from ground attack. The Russians will reportedly be making use of an existing Syrian air force base in the Damascus area.

The report was written by the news site’s military correspondent, Alex Fishman, who has a reputation for reliability.

The United States and allies began air strikes against IS a year ago. Last month American warplanes, which had been launching from aircraft carriers in the Persian Gulf and from Gulf states, began operating from an airbase in Turkey. Should the report of direct Russian intervention prove true, coordination between the Russians and Americans would be mandatory. Until now, wrote Fishman, there has been no reaction from Washington to the Russian move although the Obama administration is well aware of it.

"The Russians do not harbor offensive intentions towards Israel or other sovereign states in the area," he wrote. "Their main stated goal is batting ISIS and preserving Assad’s rule." Moscow fears the spread of the Islamic State’s influence in the former Islamic Soviet Republics unless it is stopped in the Middle East. For Iran too, halting the group’s advance is its most important immediate aim—important enough to permit cooperation with the ‘Big Satan", Washington.

Although Israel has not undertaken direct strikes against the Assad regime aimed at unseating it, it has periodically launched air strikes against missiles and other advanced armaments being transshipped through Syria by Iran to Hezbollah in Lebanon. This, theoretically at least, raises the possibility of Russian and Israeli aircraft coming into contact unless an accommodation between them is reached beforehand. During the 1973 Yom Kippur War, a number of Soviet lives were lost during Israeli raids in Damascus and Syrian ports. The two countries did not have diplomatic relations at the time. There are at present sound diplomatic relations between them.

The Russian air effort will be focused on Islamic targets in Syria. It is not clear whether the aircraft will operate over Iraq. The reported visit to Moscow last month of Iranian General Qasem Soleimani, commander of the al-Quds force, which operates outside Iranian territory, is believed to have included talks about Russian air intervention in Syria.

Informal coordination is also underway between the United States and Iran over the battle against IS in Iraq. Washington regards Iran as a central player in the struggle against the radical Islamic group.

The Ynet report said the Russians will also operate against "rebel-aligned targets" within Syria. Although all nations active in Syria and Iraq oppose IS, many support rebel groups, including the United States and other Western and Arab states. This would be a potentially explosive issue if not headed off quickly.

While Iran and Russia are interested in preserving Assad in place, each for its own reasons, most nations attacking IS are opposed to the Damascus regime. It is seen as responsible for the Syrian civil war, which has led to more than 200,000 deaths and the uprooting of millions. Throughout this period, the Russians have sent a vessel to Syria every week carrying military supplies and Tehran has been airlifting military supplies to Damascus airport. Arab media reports that the Russians are planning to double their shipments. However, with the Syrian army losing key ground to rebel forces and losing personnel through desertion and in battle it is questionable if these efforts will succeed in propping up the regime.